Endless cleated track

ABSTRACT

Disclosed herein is an endless track having a number of belts formed from strips of flexible material having tapered ends and supported for movement in a parallel spaced relation by traction bars having drive sections offset into the space between the belts. The tapered ends of the belts are spliced by a number of the traction bars.

United States Patent Trapp 51 Aug. 1, 1972 [54] ENDLESS CLEATED TRACK[72] Inventor: Robert L. Trapp, Milwaukee, Wis.

[73] Assignee: Outboard Marine Waukegan, 111.

May 8, 1970 Corporation,

[22] Filed:

121 App]. No.: 33,162

Related U.S. Application Data [63] Continuation of Ser. No. 750,105,Aug. 5,

I 1968, abandoned.

[52] U.S. Cl ..305/35 EB, 24/38 [51] Int. Cl. ..B62d 55/24 [58] Field ofSearch ..305/35, 38, 37; 24/31, 36,

[56] References Cited UNITED STATES PATENTS 3,011,576 12/1961 l-lowes..305/35 EBX 3,510,174 5/1970 Lamb ..305/35 EBX 3,362,492 l/l968 Hansen..305/35 EBX 2,461,150 2/1949 Flynn ..305/35 EB Primary Examiner-RichardJ. Johnson Attorney-Robert E. Clemency, John W. Michael, Gerritt D.Foster, Bayard H. Michael, Paul R. Puerner, Joseph A. Gemignani, Andrew0. Riteris, Spencer B. Michael and Robert K. Gerling [57] ABSTRACTDisclosed herein is an endless track having a number i of belts formedfrom strips of flexible material having tapered ends and supported formovement in a parallel spaced relation by traction bars having drivesections offset into the space between the belts. The tapered ends ofthe belts are spliced by a number of the traction bars. 3

1 Claim, 5 Drawing Figures [1P9 O O Q ENDLESS CLEATED TRACK This is acontinuation of Ser. No. 750,105, filed Aug. 5, 1968, now abandoned.

BACKGROUND OF THE INVENTION Endless tracks, particularly of the typewhich are used to provide traction for vehicles, commonly include anumber of belts interconnected by parallel traction bars or cleatsmounted on the outer surface of the belt. The track is mounted on adrive sprocket and driven by gear teeth positioned on the drive sprocketand extending radially outwardly beyond the surface of the belts tosequentially engage the traction bars or cleats mounted on the outersurface of the belts. The spacing between the gear teeth increases asthe radial distance from the drive sprocket increases and the spacingbetween the traction bars increases when the track moves around theouter surface of the drive sprocket. This variation in spacing oftenresults in irregular engagement between the gear teeth and the tractionbars. The parallel relation of the traction bars provides little lateralsupport for the vehicle.

The belts used to make up prior tracks have often been spliced byattaching metal splice halves to the ends of the belts and hingedlyinterconnecting the splice halves. The mass of the splice halves can setup an objectionable vibration at high speeds.

SUMMARY OF THE INVENTION An endless track according to the inventionincludes a number of belts interconnected for movement in a parallelspaced relation by a plurality of traction bars or cleats secured atspaced intervals to the outer surface of the belts with the drivesection of each traction bar offset into the space between the belts.The track is mounted on a drive sprocket having radially extending gearteeth arranged to engage the drive sections on the traction bars in thespace between the belts. This arrangement in the point or place ofdriving engagement between the gear teeth and the drive section of thetraction bars occurs near the root of the gear teeth where the spacingbetween the teeth is constant and the spacing between the drive sectionsremains substantially constant when the belt moves around the drivesprocket. Wear at the outer end of the gear teeth is substantiallyeliminated since the gear teeth do not extend radially outwardly beyondthe outer surface of the belts. Smooth track operation at all speeds isprovided by the track disclosed herein by using the traction bars tosplice the belts which results in an even distribution of weight in thebelts. Ribs or ridges are provided on the belts transverse to thetraction bars to improve the lateral stability of the track.

Other objects and advantages of the present invention will becomeapparent from the following description when read in connection with theaccompanying drawings in which:

FIG. 1 is a side view in section of a portion of an endless trackmounted on a drive sprocket.

FIG. 2 is a section view of the track and drive sprocket taken on line2-2 of FIG. 1.

FIG. 3 is a plan view of a point of the track showing the splice for thebelts.

FIG. 4 is a plan view of a section of an alternate or modified form ofendless track.

FIG. 5 is an end view of the modified track taken on line 4-4 of FIG. 4.I

DESCRIPTION OF THE INVENTION An endless track 10 in accordance with theinvention provides positive engagement between the gear teeth 14 on adrive wheel 12 and the traction bars 16 on the track 10 by arranging thepoint of driving engagement at or near the root of the gear teeth 14. Aportion of the endless track 10 is shown in FIG. I mounted on the drivewheel 12 which is connected to a power source such as an engine or atransmission of a vehicle. Only the drive wheel 12 is shown in thedrawing, however, it should be understood that the endless track 10 isalso mounted on idler wheels to hold the track 10 in fairly tightengagement with the drive wheel 12. The endless track 10 is driven bymeans of the gear teeth 14 on the drive wheel 12 which sequentiallyengage the traction bars or cleats 16 provided on the endless track 10.

More specifically, the drive wheel 12 includes a cen- I tral hub 18having a bore 20 to receive a drive shaft 22 from a power source (notshown). The gear teeth 14 are equally spaced in a circumferential row onthe outer surface 26 of a wheel 25 mounted on hub 18. Each gear tooth isin the form of a stub type involute tooth having a curved drive surface28.

Various means may be used to support the track 10 and in the drawings,the track 10 is shown supported by two wheels 24 mounted to rotatefreely on bearings 23 on shaft 22. A cylindrical drum secured to thewheel 25 could also be used to support the track 10.

The endless track 10 shown in FIGS. 1, through 3 includes a pair offlexible belts 30 connected for movement in parallel spaced planes bymeans of the traction bars 16 spaced at intervals on the belts 30corresponding to the width of gear teeth 14. The traction bars or cleats16 each include belt connecting sections 34 and an offset drive section36. Each traction bar 16 is secured to the belts 30 by means of rivets38 which pass through apertures 40 provided in the belt connectingsections 34 and apertures 42 in the belts 30 with the drive section 36offset into the space between the belts.

By locating the drive sections 36 between the belts 30 engagement willoccur at or near the root of the gear teeth 14 where the distancebetween the drive sections 36 remains substantially constant when thetrack 10 moves around the drive sprocket. This is shown in FIGS. 1 and 2where the drive sections 36 are shown offset into the plane of thebelts'30. The belts 30 ride on the outer surface 26 of the wheel 25 andeach drive section 36 is sequentially seated in the space between theradial surfaces 28 of the gear teeth 14. Wear of the outer surface 15 ofthe gear teeth 14 is substantially reduced, since the outer surface 15of the gear teeth extends radially outwardly only a distance sufficientto engage the drive sections 36 on the traction bars 16.

The traction bars 16 are also used to splice the belts 30. Each of thebelts 30 is formed from a strip of flexible material such as rubber,with the ends 32 cut at a diagonal or taper. The ends 32 of the beltsare placed in an abutting relation and a number of the traction bars 16,three shown in FIG. 3, are placed over the ends 32. The rivets 38 in theconnecting sections 34 of the traction bars 16 are located on each sideof the adjacently located ends 32 of the belts 30. Curling at the ends32 of the belts 30 is prevented by cutting away a portion 46 of the endof the belt.

In FIGS. 4 and 5 an alternate form of endless track 50 is shown for adrive sprocket 52 having two rows of gear teeth 54 spaced at equalintervals around the outer surface 55 of drive wheels 57. The endlesstrack 50 includes a pair of outside belts 60 and a center belt 62interconnected for movement in a spaced relation by a number of tractionbars 64 spaced at intervals corresponding to the width of the gear teeth54. Driving engagement between the gear teeth 54 and the traction bars64 is provided by means of drive sections 66 offset into the spacesbetween the belts 60 and 62. Each drive section 66, as it issequentially brought into engagement with the gear teeth on the drivesprocket, will seat in the space between the gear teeth 54.

The belts 60 and 62 are formed from strips of flexible material withtapered ends 68 and 70, respectively. The belts 60 and 62 are spliced byplacing the tapered ends 68 and 70 in abutting engagement and placing anumber of the traction bars 64 over the ends 68 and 70. The tractionbars are secured to the belts by means of rivets 61 with at least onerivet on each side of the tapered ends 68 and 70.

Lateral movement of the endless track 50 on the terrain is prevented byproviding upstanding ridges or ribs 72 on the outer edge of the outerbelts 60. The ridges 72 extend in a transverse relation to the tractionbars 64 and project radially outwardly a distance at least equal to theheight of the traction bars. This invention also includes an endlesstrack formed from a single belt. In this case, the traction bars shouldbe mounted.

on the flexible belt with the drive sections offset along each outsideedge of the belt. This type of endless track can be mounted on anddriven by a drive sprocket having one or two rows of gear teeth.

Various of the features of the invention are set forth in the followingclaims.

What is claimed is:

1. An endless track comprising a plurality of spaced and transverselyextending traction bars each having a central offset drive section, apair of flexible belts secured to said traction bars such that saidtraction bars extend substantially at right angles to the length of saidbelts and along the outside surface thereof for substantially the entirewidth of said belts, and such that said belts are located in spacedparallel relation to each other outwardly of said offset drive sections,said belts each including adjacently located diagonally cutsubstantially abutting ends secured to at least two of said tractionbars, said belts having along the outside thereof longitudinallyextending and outwardly projecting ribs.

1. An endless track comprising a plurality of spaced and transverselyextending traction bars each having a central offset drive section, apair of flexible belts secured to said traction bars such that saidtraction bars extend substantially at right angles to the length of saidbelts and along the outside surface thereof for substantially the entirewidth of said belts, and such that said belts are located in spacedparallel relation to each other outwardly of said offset drive sections,said belts each including adjacently located diagonally cutsubstantially abutting ends secured to at least two of said tractionbars, said belts having along the outside thereof longitudinallyextending and outwardly projecting ribs.